Many medical procedures employ medical grade bone cement in connection with the restoration and strengthening of bone structures. For example, surgeons commonly use bone cement in order to fill voids in bone. It is desirable to use bone cement, such as an adhesive bone cement, to hold small bone fragments in place to allow for healing, when methods such as traditional plate and screw methods of reattachment are not feasible. Only a small amount of bone cement may be required to fill small gaps between the bone fragments in order to glue the fragments together. For example, volumes of cement under one cubic centimeter may be used. In such applications, cement is typically dispensed to a bone to fill in voids or spaces in the bone or between medical devices or implants attached to or embedded within the bone. These dispensing devices may include systems as simple as syringes and as complex as electronically controlled valves.
The bone cement may be a mixture of different ingredients, and, before applying the bone cement to a repair site, the cement may be prepared by mixing a liquid monomer with a powder in a mixing device. The prepared bone cement can have various viscosities, and some may have quite a high viscosity, with a consistency like a tacky paste. For example, a typical adhesive bone cement may have a viscosity greater than 80 Pascal-seconds. Due to the high viscosity of the bone cement, it is often difficult to load the prepared cement into a syringe or other device. Indeed, the high viscosity of the bone cement requires a great amount of force to transfer the prepared bone cement from the mixing device to the syringe or other device. This disclosure describes improvements over these prior art technologies.